The field of the invention is sensors incorporating an optical fiber and a microsphere.
U.S. Pat. No. 4,269,648 teaches a microsphere bead coupling lens which can be mounted onto an end of an optical fiber after the end is initially prepared by cleaning and cleavage. An adhesive is first applied to the cleaved end. The applied adhesive end of the optical fiber is then approximately centered over a microsphere bead to be mounted. The fiber is lowered until the adhesive on the end contacts the bead. The fiber is then raised whereby the adhesive on the end holds onto the bead by surface tension so that the bead gets picked up as the fiber is raised; and, due to the combination of surface tension and gravity, the bead lens is moved by the adhesive until the lens is aligned with, or very close to, the central axis of the fiber. Subsequently, the adhesive on the fiber end is cured by either ultraviolet-curing or heat-curing.
U.S. Pat. No. 4,965,701 teaches an illumination curtain in which a support housing includes a spaced series of downwardly descending tubular members receiving therewithin electrical transmission line in communication with spaced illumination bulbs mounted within translucent spheres. The translucent spheres are mounted onto the tubing members at spaced intervals therealong. The tubular members may encase a circuitous optical fiber with a rear terminal end aligned with an opening of an egg-shaped housing containing an illumination bulb therewithin to provide an enhanced visual effect of the illumination curtain.
U.S. Pat. No. 4,965,091 teaches a sol-gel procedure is described for making display devices with luminescent films. The procedure typically involves hydrolysis and polymerization of an organometallic compound together with selected luminescent ions, and coating of a substrate and then heat treatment to form a polycrystalline layer.
U.S. Pat. No. 4,785,814 teaches an optical probe which is for use in measuring pH and oxygen content in blood in a blood vessel within a living body and which includes an optical fiber, a membrane and a plurality of microspheres. The optical fiber is elongated and flexible and has a proximal end and a distal end which is adapted to be inserted into a blood vessel. The membrane is secured to the distal end of the optical fiber and receives light therefrom and returns light therethrough to the proximal end. The membrane is constructed of hydrophilic porous material containing a pH sensitive dye. The microspheres are embedded in and carried by the membrane. The microspheres are constructed of a hydrophobic material. Each microsphere carries a fluorescent dye quenchable with oxygen. Consequently, when light is supplied to the proximal end of the optical fiber, it is conveyed to the membrane. This causes the pH sensitive dye to react and light is conveyed through the optical fiber having an intensity level indicative of the pH level in the blood. The oxygen sensitive dye fluoresces and light is transmitted to the proximal end of an intensity which varies with the partial pressure of oxygen.
U.S. Pat. No. 4,939,376 teaches a light collection device which is for use in a flame emission detection system such as an on-line, real-time alkali concentration process stream monitor and which includes a sphere coated on its interior with a highly diffuse reflective paint which is positioned over a flame emission source, and one or more fiber optic cables which transfer the light generated at the interior of the sphere to a detector. The diffuse scattering of the light emitted by the flame uniformly distributes the light in the sphere. The light collection device provides enhanced sensitivity and reduces the noise associated with flame emission detectors, and can achieve substantial improvements in alkali detection levels.
U.S. Pat. No. 5,051,595 teaches a fiber optic flame detection and temperature measuring system which includes an optical fiber having a lens at a distal end to direct radiation from a fire into the optical fiber to a radiation detector. The optical fiber is doped with a material which has been selected for its temperature dependent fluorescent emission characteristics.
U.S. Pat. No. 5,176,882 teaches an optical fiber which is used in conjunction with a sensor which is capable of sensing more than one analyte. A doped polymer is formed utilizing a hydrophilic polymer which immobilizes a pH sensitive dye and a potassium sensistive fluorescence dye.
U.S. Pat. No. 4,921,788 teaches a kit for performing a competitive immunoassay which utilizes nucleic acid oligonucleotide chains for the detection of analytes, such as drugs, substances of abuse, hormones, poisons, organic compounds, peptides, proteins and the like. The kit includes a hapten-oligonucleotide complex, a complementary oligo-nculeotide chain for conjugating with the hapten-oligonucleotide complex, an antibody specific for the hapten and a flourescent label such as ethidium bromide having an affinity for nucleic acid duplexes formed from the hapten-oligonucleotide complex and the complementary oligonucleotide chain. A detector for detecting the presence of the florescent label such as a U. V. transilluminator, U. V. lightbox and fluorescence spectrophotometer is utilized to detect color intensity and fluorescence of the dye. The method can be performed in solution, or on a solid "dipstick" on which the reagents for the immunoassay have been immobilized.
U.S. Pat. No. 4,663,277 teaches a virus detection method in which viruses are detected by an immunoassay method in which an extended solid phase coated with antiviral antibody is employed to bind and remove virions from a specimen by forming an immuno-complex with antigens of the virions. A mobile solid phase includes a dispersion of microspheres coated with the antiviral antibody is used to bind the microspheres to antigens associated with the immuno-complex, and the presence of bound microspheres is detected. The detection sensitivity is amplified by the ability to more readily detect the microspheres, which may be dyed or labelled. The extended solid phase advantageously may be in the form of a dipstick which can be easily contacted with the specimen. A virus detection kit provides the extended solid phase and mobile solid phases, each coated with antiviral antibodies.
U.S. Pat. No. 4,983,369 a process for producing highly uniform microspheres of silica having an average diameter of 0.1-10 microns from the hydrolysis of a silica precursor, such as tetraalkoxysilanes, which is characterized by employing precursor solutions and feed rates which initially yield a two-phase reaction mixture.
U.S. Pat. No. 4,943,425 teaches a method of making high purity, dense silica of large particle size. Tetraethylorthosilicate is mixed with ethanol and is added to a dilute acid solution having a pH of about 2.25. The resulting solution is digested for about 5 hours, then 2N ammonium hydroxide is added to form a gel at a pH of 8.5. The gel is screened through an 18-20 mesh screen, vacuum baked, calcined in an oxygen atmosphere and finally heated to about 1200.degree. C. in air to form a large particle size, high purity, dense silica.
U.S. Pat. No. 4,132,560 teaches a pigmented silica microsphere which has an average diameter from 2 to 100 microns and which consists essentially of from 10% to 70% by weight of particulate pigment, dispersed throughout a microporous silica matrix and, optionally, containing a coating of dense amorphous silica. The microspheres are produced by acidifying a water-in-oil emulsion. The pigmented silica microspheres are particularly useful as opacifying agents for coating compositions and as fillers for paper.
U.S. Pat. No. 4,677,138 teaches a high yield process for producing homopolymeric polyaldehyde microspheres which can be prepared in yields of up to about 90% by preparing an aqueous solution consisting essentially of a suitable concentration of an alpha/beta-ethylenically unsaturated aldehyde and a suitable concentration of an appropriate surfactant under suitable conditions such that the surfactant has a net electrostatic charge. The solution, which may also contain a ferrofluidic material, fluorescent dye or additional solvent, is then irradiated under an inert atmosphere with a sufficient dose of gamma radiation to effect polymerization and the monodisperse homopolymeric polyaldehyde microspheres so produced are recovered.
U.S. Pat. No. 4,991,150 teaches a stress sensing material, either piezoelectric or ferroelectric, which is in intimate electrical communication with an electroluminescent material in order to produce light at an amplitude dependent on the stress applied to the stress sensing material. The light signal is transmitted from the electroluminescent material by an optical fiber to an optical signal detector. The electroluminescent material includes a light emitting diode as a small electrical short circuit load across two otherwise insulated faces of a piezoelectric or ferroelectric element.
U.S. Pat. No. 4,997,597 teaches a solid state radioluminescent composition for light source which includes an optically clear polymer organic matrix containing tritiated organic materials and dyes capable of "red" shifting primary scintillation emissions from the polymer matrix. The tritiated organic materials are made by reducing, with tritium, an unsaturated organic compound that prior to reduction contains olefinic or alkynylic bonds.
U.S. Pat. No. 4,927,578 teaches virtually uncrosslinked polyacetylenes in film form are prepared by polymerization of acetylene using a liquid catalyst system consisting of an organicaluminum compound and a titanate in the form of a solution in a viscous inert liquid on a substrate to which the catalyst solution is applied, by a process in which, after the polymerization, the polymer is treated with a strong reducing agent which is inert to the organoaluminum catalyst component, the polymer is, if desired, oriented and is freed from residual catalyst and reducing agent by washing with a liquid, doped with a strong electron acceptor or electron donor in a conventional manner to increase the conductivity and dried, and the materials thus obtained are, if desired, covered with a layer or sheath of nonconductive material.
U.S. Pat. No. 4,968,524 teaches an organic substance which has a polyacetylene linkage exhibiting electrical conductivity and nonlinear optical effect. A process for producing the organic substance having a polyacetylene linkage includes the steps of immersing a substrate having a hydrophilic surface in a solution of a substance containing an acetylene group and a chlorosilane group dissolved in a nonaqueous organic solvent, thereby subjecting the substance containing an acetylene group and a chlorosilane group to chemical adsorption on the surface of the substrate, subjecting the substance to polymerization reaction by the use of radiation such as X-rays, electron beams, gamma-rays, or the like, and thereby producing a polyacetylene.
U.S. Pat. No. 4,906,570 teaches modified polymers which are based on polyvinylene carbonate and/or polyhydroxymethylene containing covalently bonded units which are derived from particular alkoxylated compounds. Polymerization is carried out in the presence of the alkoxylated compounds and a particular dispersion stabilizer. The modified polymer is suitable as a carrier for biologically active substances or for affinity chromatography.
U.S. Pat. No. 4,895,445 teaches a spectrophotometer for operating in the reflection or transmission mode includes a collecting lens for directing non-collimated light from the sample being analyzed onto a diffraction grating. An imaging lens focuses diffracted light onto an array of sensors. Because the collecting lens directs non-collimated light at the grating, a substantially linear spectrum can be imaged on the array.
U.S. Pat. No. 4,920,056 teaches an apparatus for automatic microbatch reaction including a reactor having a reaction chamber, such as a 1.5 milliliter plastic centrifuge tube having a conical bottom. An automatically actuated injection valve is used to inject less than 1 milliliter of a sample into the reaction chamber. One or more automatically actuated reagent valves are used to introduce respective pressurized reagents into the reaction chamber to process the sample. The volume of the reagent(s) introduced into the reaction chamber is less than 1 milliliter and controlled by the on time of the respective reagent valve. The automatically actuated valves are controlled by a computer based timer. A sensor positioned in the chamber, such as a pH electrode, can be used to analyze the processed sample in place or the processed sample can be analyzed by flowing it from the reaction chamber through a flow-through detector, such as a flow-through spectrophotometer.
U.S. Pat. No. 4,952,817 teaches a test system in a stand-alone chassis without a power cord. The testing subsystem, such as a spectrophotometer is microprocessor-controlled, and the microprocessor is disconnected from the battery during normal operation. An ancillary integrated circuit controls the power supply to the microprocessor, and periodically powers up a proximity sensor subsystem, such as a photodiode/LED pair, without powering up the microprocessor. The ancillary circuit powers up the microprocessor IF the proximity sensor subsystem, after being activated, indicates that a sample has been inserted by a user. The microprocessor can then operate the testing subsystem, and provide output data to a display driver accordingly.
U.S. Pat. No. 4,931,646 teaches a multichannel coincidence nuclear detector system for spectral charactertion of nuclear radiation sources at a remote location. The system is designed to detect and classify the radiation source in unfriendly territory and to provide a radio link back to a friendly receiver user station. The sensing elements are comprised of a plurality of plastic scintillator fiber sensors which may be several meters long and with each fiber having a different spectral sensitivity to gamma and neutron sources. Each of the scintillator fibers is connected to a transmitting optical fiber which may be 1 kilometer or more in length. The plurality of optical fibers transmit the optical signal generated by the radiation from a nuclear source impinging on the scintillator fibers to an electronic system. The electronic system is a sealed self contained battery operated device which includes a photomuliplier detector and microprocessor based signal processing and data storage. The microprocessor compares the input signals from each scintillator fiber and determines the energy source. The data is stored in the microprocessor and may be interrogated by a radio frequency link to at a receiver station many kilometers away. The fiber sensors, optical fibers, and the electronics system including a transmitting antenna are all covertly positioned to prevent being observed by an unauthorized person.
An article, entitled "Sol-Gel Optical pH Sensors," published in the Proceedings of the Society of Photo-Optic Instrumentation Engineers, Volume 1758, Sol-Gel Optics II, pages 464-475, discloses that a sol-gel process for preparing a thin film of amorphous and transparent oxide materials doped with fluorescein dye. The thin film is placed onto a flat glass substrate. The thin film and the flat glass substrate form a pH sensor.